142 



NA TURE 



[December 3, 1908 



the pit which could not liave been produced by llie stag- 

 horii piclts usually employed by the workmen in prehistoric 

 times. He guessed that they were the result of blows by 

 a stone axe, the edge of which had become blunted and 

 battered in a peculiar way by use. When the axe was 

 subsequently found imbedded in the chalk, it was immedi- 

 ately recognised to be the identical tool with which these 

 peculiar markings had been made. There can be no 

 question, therefore, of the genuineness of the implement, or 

 that the mutilation of the edge is contemporaneous with 

 the period in which the tool was made and used. It thus 

 supplies conclusive evidence that the pit was excavated 

 during the period when polished stone implements were 

 in use. 



The annual report of the Transvaal Meteorological 

 Department for the year ended June 30, 1907, shows that 

 there is a considerable increase in the number of observers, 

 all of which are volunteers or attached to other depart- 

 .nients. The results nf observations are arranged in appen- 

 dices, as in previous reports ; in many cases only means 

 are printed, but the individual observa,tions are available 

 for any inquiry in case of need. In addition to the ordinary 

 weather forecasts for the ensuing twenty-four hours, which 

 are exhibited at every postal telegraph office, weekly fore- 

 casts have been prepared for the Agricultural Department 

 when required ; these are necessarily more indefinite than 

 the daily forecasts. Investigations on various meteor- 

 ological subjects are in such progress as the limited staff 

 will permit ; several papers have been communicated during 

 the year to the Metcorologische Zeitschrift and other scien- 

 tific periodicals. It may be mentioned that a new thermo- 

 meter screen, constructed by Mr. D. E. Hutchins, with 

 double laths instead of louvres, as in the Stevenson screen, 

 has been under examination during a year. It costs less 

 than the louvred screen, while the results obtained are 

 practically the same. 



The first number of a new scientific monthly, entitled 

 Ion, a Journal of Electronics, Atomistics, lonology. Radio- 

 activity, and liaumchemistry, has just appeared. It is 

 quarto in form, and contains eighty pages, well printed, 

 with a fair number of diagrams, some of which have, 

 however, been prepared from very rough drawings. About 

 fifty pages are devoted to three articles on " The Charge 

 carried by the a Particles," by Mr. F. Soddy ; " Uranium 

 and Geology," by Prof. Joly ; and "Transmission of 

 Energy in the World of Electrons," by Dr. H. W. Julius. 

 Fifteen pages are devoted to reports on the various fields 

 of work covered by the periodical, and three pages to 

 reviews of ten books. Prof. Joly's paper is evidently an 

 address, but no indication is given as to where it was 

 delivered, and the reports would be increased in value if 

 references to further .sources of information were added. 

 Several of the contributions require more careful editing, 

 as they contain expressions which convey little meaning 

 to a reader not well versed in German, but this may be 

 due to the journal being printed in Germany. It would 

 be a great convenience to its readers if it could be issued 

 with the edges of the leaves cut. Notwithstanding these 

 minor defects, which can be easily remedied in future 

 numbers. Ion provides a physicochemical journal long 

 needed in this country. 



Until 1893, the conservation of mass in chemical re- 

 actions was tacitly assumed in all chemical work. In that 

 year H. Landolt published a memoir in which the 

 validity of this assumption was submitted to an experi- 

 mental control under modern conditions ; in no case were 

 any changes in the total mass of the reacting substances 

 NO. 2040, VOL. 79] 



observed outside the limits of experimental error. In a 

 second paper, however, published in 1906, experiments 

 carried out with an improved apparatus appeared to show 

 a slight decrease in forty-two out of fifty-four observa- 

 tions. In a series of control experiments, carried out with 

 vessels in which no chemical reactions were taking place, 

 this decrease was not observed, and Landolt suggested 

 the emission of electrons during chemical reactions as a 

 possible cause of this loss. In last month's number of the 

 Zeitschrift filr physikalische Chemie the same author con- 

 tributes a third paper on this subject. In this the slight 

 losses noticed in the earlier paper are traced down to 

 minute volume changes in the glass vessels employed, the 

 after effects of the slight temperature changes accompany- 

 ing the chemical phenomena. The final conclusion drawn 

 from the results of all the experiments is that no change 

 of mass can be detected as a result of chemical reactions, 

 and the law of the conservation of mass in this case is true 

 within the very small limits of experimental error. Apart 

 from the interest attaching to the rigid proof of this law, 

 universally assumed in all chemical work, the present 

 memoir goes very fully into the effects of changes of 

 temperature on the volume and moisture films of glass 

 vessels, a question arising in all chemical and physical 

 researches involving the accurate weighing of substances 

 in glass. 



A CATALOGUE of electrical novelties received from Messrs. 

 F. Darton and Co., Clerkenwell Optical Works, London, 

 E.C., contains descriptions of many simple and cheap 

 motors, dynamos, coils, and other apparatus. The list 

 should be of service in suggesting suitable Christmas pre- 

 sents for youths and others interested in electricity. 



\ LIST of microscopes and accessories just issued by 

 -Messrs. Ross, Ltd., the well-known manufacturing 

 opticians, should be seen by everyone contemplating the 

 purchase of a microscope for pleasure or work in various 

 departments of science. The instruments described are of 

 a high level of construction and efficiency, and each part 

 has been designed with care. The catalogue also contains 

 particulars of new photomicrographic apparatus. 



OUR ASllWNO.MICAL tui^unuyi. 



Morehouse's Co.met, 1908c. — Writing to the Astrono- 

 niischc Nacitrichien (No. 4284, p. 194, November 21), 

 Prof. E. C. Pickering transmits a message from Prof. 

 Frost directing attention to the increased brightness of 

 Morehouse's comet towards the end of October. It was 

 easily seen, at the Verkes Observatory, with the unaided 

 eye, whilst with a small field-glass three or four degrees 

 of tail became visible. With the Zeiss ultra-violet 

 objective-prism camera three exposures on spectrum plates 

 were made by Mr. Parkhurst and Prof. Frost, two of 

 them each of one hour's duration. At the time of writing 

 the measurement of the spectra was not complete, but 

 Prof. Frost suggests that they are of the ordinary hydro- 

 carbon type. As no continuous spectrum is perceptible, it 

 is concluded that the radiations at the time of exposure 

 (October 28) were, to a very large extent, intrinsic. 



Prof. Pickering reports that photographs taken at the 

 Harvard Observatory on October 30 show a tail at least 

 nine degrees in length, much longer than on previous 

 nights. 



Further evidence of the changes which took place in the 

 appearance of the comet, especially at the end of Sep- 

 tember and beginning of October, comes from Herr 

 Winkler, of Jena, who observed with a 6-inch refractor. 

 In his notes, published in No. 4280 of the Astronomischc 

 Nachrichten (November 6), he states that no tail was 

 seen on October i, although on September 28 a tail 40' 

 in length was observed. 



